A HEDGE fund manager in America has sparked fury among health experts and patients by buying the rights to a drug used to treat conditions related to Aids and cancer, and increasing its price by 5,000pc overnight.

Martin Shkreli, a bullish 32-year-old New York businessman, who revels in a lavish lifestyle, purchased Daraprim in August. The drug is used to treat toxoplasmosis, a parasite infection that can cause life-threatening problems for those with weakened immune systems, such as unborn babies, Aids sufferers and some cancer patients.

The pills were being sold for $13.50 (€12) each, but Mr Shkreli's company, Turing Pharmaceuticals, increased the price immediately to $750. Treatment requires a course of 100 pills.

"This isn't the greedy drug company trying to gouge patients, it is us trying to stay in business," said Mr Shkreli, claiming that many patients use the drug for less than a year and that the price was now more in line with those of other drugs for rare diseases. The drug was first developed in the 1940s, and is not commonly prescribed, but still vital. In 2014, it was prescribed 8,821 times.

"This is still one of the smallest pharmaceutical products in the world. It really doesn't make sense to get any criticism for this," he said.

Yet Mr Shkreli has not helped himself by posting a series of messages on social media in which he flaunted his wealth and bragged about his $5m charity donations. "Every time a drug goes generic, I grieve," he tweeted in 2012. "Let us not mourn the dearly departed, instead celebrate the profits and new assets it brought us."

In his Instagram feed, he boasts of drinking bottles of 1969 Petrus and 1982 Chateau Latife-Rothschild.

In July and August he was cruising around in his boat, and posting photos of a helicopter ride back to New York.

In response to his critics, he told them to refer to 'The Way I Am', an Eminem song with the lyrics: "I don't care who was there and saw me destroy you; go call you a lawyer, file you a lawsuit; I'll smile in the courtroom and buy you a wardrobe."

Social media users besieged him, angry at his price hike, but Mr Shkreli was defiant, saying "Ain't my fault" when told that his decision was hurting the poorest people. His Twitter feed was full of quotes from other people, who he retweeted praising his business acumen.

But health care professionals reacted angrily to the decision.

The Infectious Diseases Society of America and the HIV Medicine Association sent a joint, open letter to Turing Pharmaceuticals earlier in September, complaining that the sudden, steep price increase for Daraprim was "unjustifiable for the medically-vulnerable patient population" and also that it was "unsustainable for the health care system".